RequestParam.java

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.bind.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Annotation which indicates that a method parameter should be bound
 * to a web request parameter. Supported for {@link RequestMapping}
 * annotated handler methods in Servlet and Portlet environments.
 *
 * @author Arjen Poutsma
 * @author Juergen Hoeller
 * @since 2.5
 * @see RequestMapping
 * @see org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter
 * @see org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestParam {

	/**
	 * The request parameter to bind to.
	 */
	String value() default "";

	/**
	 * Whether the parameter is required.
	 * <p>Default is <code>true</code>, leading to an exception thrown in case
	 * of the parameter missing in the request. Switch this to <code>false</code>
	 * if you prefer a <code>null</value> in case of the parameter missing.
	 */
	boolean required() default true;

}